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Breathing is normally an unconscious, involuntary, automatic process. The pattern of motor stimuli during breathing can be divided into an inhalation stage and an exhalation stage. Inhalation shows a sudden, ramped increase in motor discharge to the respiratory muscles (and the pharyngeal constrictor muscles ). [ 5 ]
Brain control of exhalation can be broken down into voluntary control and involuntary control. During voluntary exhalation, air is held in the lungs and released at a fixed rate. Examples of voluntary expiration include: singing, speaking, exercising, playing an instrument, and voluntary hyperpnea. Involuntary breathing includes metabolic and ...
Laryngospasm is an uncontrolled or involuntary muscular contraction of the vocal folds. [1] It may be triggered when the vocal cords or the area of the trachea below the vocal folds detects the entry of water, mucus, blood, or other substance. It may be associated with stridor or retractions.
The dorsal respiratory group (DRG) has the most fundamental role in the control of respiration, initiating inspiration (inhalation). The DRG is a collection of neurons forming an elongated mass that extends most of the length of the dorsal medulla. They are near to the central canal of the spinal cord, and just behind the ventral group.
A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes.As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually ...
This region appears to control the epipharyngeal, intrinsic laryngeal and respiratory muscles, and the combined activity of these muscles serve as the basis for the generation of a sneeze. [4] The sneeze reflex involves contraction of a number of different muscles and muscle groups throughout the body, typically including the eyelids.
The process of breathing does not fill the alveoli with atmospheric air during each inhalation (about 350 ml per breath), but the inhaled air is carefully diluted and thoroughly mixed with a large volume of gas (about 2.5 liters in adult humans) known as the functional residual capacity which remains in the lungs after each exhalation, and ...
The alveoli are the dead end terminals of the "tree", meaning that any air that enters them has to exit via the same route. A system such as this creates dead space, a volume of air (about 150 ml in the adult human) that fills the airways after exhalation and is breathed back into the alveoli before environmental air reaches them.